of the bridges in are structurally deficient.
That is the national average of 9.4%.

Percent structurally deficient bridges by county

  • 0
  • 20
  • 40
  • 60
  • 80
  • 100%

Bridges are rated by a sufficiency rating that is an overall measure based on inspector ratings of many aspects of the bridge’s top deck and underlying structure. According to the National Bridge Inventory, the worst bridges, generally with a score below 50 percent, are classified as “structurally deficient” due to at least one defect that requires attention. Bridges that are “functionally obsolete” cannot handle the required traffic needs. A low score does not mean that a bridge will fall, but it indicates that it needs repair. Bridges with posted load limits are in greatest need of repair.

Here's how that compares with the rest of the state's counties:

Percent structurally deficient

Percent functionally obsolete

Federal financing has been prioritized for bridges with the lowest sufficiency scores. Here is a closer look at a sample of counties with high rates of structurally deficient bridges from around the country. 

Boston

11.7% structurally deficient

54.5% functionally obsolete

Compared with the rest of the state

50

0

100%

S.D.

F.O.

Suffolk County has the second highest rate of structurally deficient bridges in Massachusetts after Franklin County in the western part of the state, which has nearly 15 percent structurally deficient bridges. More than half of the bridges in Suffolk and Norfolk counties (just south of Boston) are functionally obsolete.

Schuylkill County, Pa.

34.6% structurally deficient

10.2% functionally obsolete

Compared to the rest of the state

50

0

100%

S.D.

F.O.

Schuylkill County has the highest rate of structurally deficient bridges in Pennsylvania but less than the average rate of functionally obsolete bridges, falling behind Philadelphia, which has the highest rate with more than one-third of its 579 bridges functionally obsolete.

Nemaha County, Neb.

54.6% structurally deficient

1.6% functionally obsolete

Compared with the rest of the state

50

0

100%

S.D.

F.O.

Nemaha County has the highest rate of structurally deficient bridges in Nebraska, followed closely by Pawnee County at 52 percent. However, Nemaha has one of the lowest rates of functionally obsolete bridges. More than half of the 204 bridges in York County, Neb., are good, but the county has the highest rate of functionally obsolete bridges at 22 percent.

The latest data available is the 2015 National Bridge Inventory. The data is created locally and compiled by the Federal Highway Administration, so the status of some bridges may have changed since the inspection referenced here. Some location data may not be exact and some location information may not be available for some small bridges. Federal rules govern the inspections, but inspections are generally done locally, so each inspector may reach different conclusions. New bridges or bridges that have been recently rebuilt are not classified as either “structurally deficient” or “functionally obsolete,” so they would not be included here. Only counties with bridges are included.

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